Symptom

Msg 2546, Level 16, State 1:So looking on what a update all statistics <Tablename> with sampling=50 does in sam__get_apl_pages and then sam_get_ptn_nextpage this could well be related to the corruption we see on this tables.

Msg 7949, Level 18, State 1:Server 'masterdataservice', Line 1:The number of pages used and unused for object 1264004503 index 0 partition 1264004503 on allocation page 625664 do not match the counts in the OAM entry.